I was in for this, but I really like the idea of getting one in Saddle to match my pen roll. I hear that the kangaroo is more durable and/or less likely to show wear. How well will the leather hold up in my pocket?

The cowhide leather holds up really well. The kangaroo leather is a little slimmer, and over time it takes the shape of what you put in it. Whereas when the cowhide breaks in it gets softer and gets a patina. The kangaroo is a more premium leather, but only by a bit. Both have their pros and cons, and a matching set is a great idea.